Method for forming dual damascene pattern

ABSTRACT

A method for forming a dual damascene pattern includes preparing a multi-functional hard mask composition including a silicon resin as a base resin, wherein the silicon resin comprises about 20 to 45% silicon molecules by weight, based on a total weight of the resin; forming a deposition structure by sequentially forming a self-arrangement contact (SAC) insulating film, a first dielectric film, an etching barrier film, and a second dielectric film over a hardwiring layer; etching the deposition structure to expose the hardwiring layer, thereby forming a via hole; coating the multi-functional hard mask composition over the second dielectric film and in the via hole to form a multi-functional hard mask film; and etching the resulting structure to expose a part of the first dielectric film using a photoresist pattern as an etching mask, thereby forming a trench having a width greater than that of the via hole.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.11/812,910 filed on Jun. 22, 2007, now U.S. Pat. No. 7,811,929 whichclaims priority of Korean patent application number 10-2006-0132045filed on Dec. 21, 2006. The disclosure of each of the foregoingapplications is incorporated herein by reference in its entirety.

BACKGROUND

The present invention relates generally to semiconductor processing.More particularly, the present invention relates to a method for forminga dual damascene pattern.

As the semiconductor industry develops Ultra Large Scale Integration(ULSI) devices, reducing a device to a sub-half-micron size increasesthe circuit density, thereby causing a resistance-capacitance (RC) delayand copper reactive ion etching (RIE). In a process for forming a bitline pattern for devices of a reduced size, the pattern may be bridgedor collapsed.

In order to prevent bridging and/or collapsing of the pattern and toimprove the layout of the device, a dual damascene process has beendeveloped. The dual damascene process can be used when it is impossibleto pattern a metal material by a conventional etching technology due tothe reduction of the device size, or it is difficult to fill a lowdielectric material in a deep contact etching process for forming aconventional metal line.

By the dual damascene process, a contact line structure is formed. Thecontact line structure may include an aluminum metal line and an oxidefilm. Alternatively, the contact line structure may include a coppermetal line and a low dielectric constant (low-k) material for reducingthe RC delay in a LSI process.

Instead of a deposition structure including polysilicon, tungsten, anitride film, and an oxide film as a hard mask, a deposition structureincluding an insulating film and an amorphous carbon layer is used in anetching process for forming a pattern of below 80 nm for semiconductordevices of a smaller size. The deposition structure secures an etchingselectivity to a lower layer and has a faster etching speed than that ofa photoresist and an antireflection film.

However, a process using the insulating film/amorphous carbon layer iscomplicated. In addition, the manufacturing cost is high, because achemical vapor deposition (CVD) process is involved.

Recently, a multi-functional hard mask film, which serves as an organicanti-reflection film and a hard mask film, is developed to simplify theprocess.

SUMMARY

Various embodiments consistent with the present invention are directedto providing a method for forming a dual damascene pattern.

In one aspect, there is provided a method for forming a dual damascenepattern comprising a via pattern, which includes filling a via contacthole with a multi-functional hard mask composition containing a largeamount of silicon molecules, thereby simplifying the process for forminga metal line.

According to one embodiment, a method for forming a dual damascenepattern comprises: preparing a multi-functional hard mask compositionincluding a silicon resin as a base resin, wherein the silicon resincomprises about 20 to 45% silicon molecules by weight, based on a totalweight of the resin, forming a deposition structure by sequentiallyforming a self-arrangement contact (SAC) insulating film, a firstdielectric film, an etching barrier film, and a second dielectric filmover a hardwiring layer, etching the deposition structure to expose thehardwiring layer, thereby forming a via hole, coating themulti-functional hard mask composition over the second dielectric filmand in the via hole to form a multi-functional hard mask film, andetching the resulting structure to expose a part of the first dielectricfilm using a photoresist pattern as an etching mask, thereby forming atrench having a width greater than that of the via hole.

The method further comprises filling a metal material in the trench by asubsequent process to form a metal line, after removing themulti-functional hard mask film.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withdrawings will be provided by the Office upon request and payment of thenecessary fee.

FIGS. 1 a through 1 d are cross-sectional diagrams illustrating a methodfor forming a dual damascene pattern comprising a trench pattern.

FIGS. 2 a through 2 d are cross-sectional diagrams illustrating a methodfor forming a dual damascene pattern comprising a via pattern.

FIGS. 3 a through 3 f are cross-sectional diagrams illustrating a methodfor forming a dual damascene pattern comprising a via pattern.

FIGS. 4 a through 4 e are cross-sectional diagram illustrating a methodfor forming a dual damascene pattern according to one embodimentconsistent with the present invention.

FIGS. 5 a and 5 b are scanning electron microscopy (SEM) photographsillustrating a resultant multi-functional hard mask film.

FIGS. 6 a through 6 d are diagrams illustrating reflectivity simulationof a substrate having the multi-functional hard mask film.

DETAILED DESCRIPTION

A dual damascene process may include forming a dual damascene patterncomprising a trench pattern or a via pattern depending on structuresobtained by an etching process.

FIGS. 1 a through 1 d are cross-sectional diagrams illustrating a methodfor forming a dual damascene pattern comprising a trench pattern.

The method includes forming a self-align contact (SAC) insulating film 3over a hardwiring layer 1, forming a first low dielectric film 5 overSAC insulating film 3, forming a nitride film 7 over first lowdielectric film 5, forming a second low dielectric film 9 on nitridefilm 7. The method further includes an etching process, which isperformed on nitride film 7 and second dielectric film 9 to expose apart of first dielectric film 5, thereby forming a trench 10 (see FIG. 1a). An anti-reflection film 11 is formed on the second low dielectricfilm 9 and the exposed part of first dielectric film 5, and aphotoresist film 13 is formed on the anti-reflection film 11 and filledin trench 10 with a portion of anti-reflection film 11 in trench 10being exposed. The exposed portion of anti-reflection film 11 has anarea smaller than that of the previously exposed part of firstdielectric film 5. Further, an etching process is performed on theresultant structure to expose a part of hardwiring layer 1, therebyforming a via hole 14 having a smaller width than that of trench 10 (seeFIGS. 1 b and 1 c). The anti-reflection film 11 and photoresist film 13are removed, and a metal material 15 is formed on the structure to forma metal line (see FIG. 1 d).

In order to obtain a lower k (dielectric constant) value, first andsecond dielectric films 5 and 9 may include a porous dielectric materialhaving a higher etching speed than that of a conventional dielectricfilm. As a result, the porous dielectric material may be unstable,because the etching speed of the porous dielectric material is fasterthan the etching speed of the photoresist material of photoresist film13 that filled trench 10.

FIGS. 2 a through 2 d are cross-sectional diagrams illustrating a methodfor forming a dual damascene pattern comprising a via pattern.

The method includes forming an SAC insulating film 23 on a hardwiringlayer 21, forming a first low dielectric film 25 on SAC insulating film23, forming a nitride film 27 on first low dielectric film 25, andforming a second low dielectric film 29 on nitride film 27. The methodfurther includes an etching process, which is performed on SACinsulating film 23, the first low dielectric film 25, nitride film 27,and second low dielectric film 29 to expose a part of hardwiring layer21, thereby forming a via hole 30 (see FIG. 2 a). An anti-reflectionfilm (not shown) and a photoresist film 31 are formed over seconddielectric film 29 including via hole 30 (see FIG. 2 b). Photoresistfilm 31 is formed over the anti-reflection film. The resulting structureis etched using the photoresist film 31 as an etching mask to expose apart of first dielectric film 25, thereby forming a trench 33 (see FIG.2 c). A washing process is performed on the resulting structure toremove the anti-reflection film and photoresist film 31. And a metalmaterial 35 is formed on the resulting structure to form a metal line intrench 33 and via hole 30 (see FIG. 2 d).

A subsequent etching process for forming a trench is unstable, becausethe photoresist material of photoresist film 31 used in the above methodhas a low etching selectivity.

FIGS. 3 a through 3 f are cross-sectional diagrams illustrating a methodfor forming a dual damascene pattern comprising filling a via contacthole with a general gap fill material.

The method includes forming an SAC insulating film 43 over a hardwiringlayer 41, forming a first low dielectric film 45 over SAC insulatingfilm 43, forming a nitride film 47 over first low dielectric film 45,and forming a second low dielectric film 49 over nitride film 47. SACinsulating film 43, first low dielectric film 45, nitride film 47, andsecond low dielectric film 49 are etched to expose hardwiring layer 41,thereby forming a via hole 50 (see FIG. 3 a). A gap fill material 51 isformed over the second dielectric film 49 and in via hole 50 (see FIG. 3b). A planarization process is performed on the resulting structure toexpose second dielectric film 49 and gap fill material 51 (see FIG. 3c). An anti-reflection film 53 is formed on the exposed seconddielectric film 49 and gap fill material 51, and a photoresist pattern55 is formed on anti-reflection film 53 (see FIG. 3 d). An etchingprocess is performed over the resulting structure using photoresistpattern 55 as an etching mask to expose first low dielectric film 45,thereby forming a trench 56 having a larger width than that of via hole50 (see FIG. 3 e). A washing process is performed on the resultingstructure to remove anti-reflection film 53 and photoresist pattern 55.And, a metal material 57 is formed on the resulting structure to form ametal line (see FIG. 3 f).

The method described above includes forming an anti-reflection film,because gap fill material 51 does not control a substrate reflectivitylike a conventional anti-reflection film. As a result, the process iscomplicated.

In a specific embodiment consistent with the present invention, amulti-functional hard mask composition comprises: i) a silicon resinpresent in an amount ranging from about 30 to 70 parts by weight basedon the total weight of the composition; and ii) the residual organicsolvent as main elements. The composition may optionally furthercomprise: iii) a compound represented by Formula 1 or 2 (below); and/oriv) a thermal acid generator or a photoacid generator.

wherein R_(a)˜R_(d) may individually be a hydrogen (H) or a linear orbranched C₁˜C₅ alkyl group, which may be substituted, e is an integerranging from 5 to 500, f is an integer ranging from 0 to 5, and g is aninteger ranging from 1 to 5.

The molecular weight of the compound represented by Formula 1 rangesfrom about 500 to 50,000. The hydroxyl compound of Formula 2 preferablyhas a molecular weight ranging from about 100 to 10,000. The hydroxylcompound is represented by a compound including a benzene ring and adiol structure. For example, the hydroxyl compound is represented byresorcinol or 1,4-benzenedimethanol. Preferably, the compoundrepresented by Formula 1 or 2 is present in an amount ranging from about20 to 200 parts by weight based on 100 parts by weight of the siliconresin. The hydroxyl compound is present in an amount ranging from about10 parts by weight to 80 parts by weight, based on 100 parts by weightof the silicon compound of Formula 1.

The silicon resin includes a silicon (Si) molecule present in an amountranging from about 20 to 45 wt % based on the total weight of the resin.The molecular weight of the silicon resin ranges from about 300 to30,000.

The silicon resin includes one or more selected from compoundsrepresented by Formulas 3 through 7 (below) as a base resin.

wherein R₁˜R₂ may individually be a hydrogen (H) or a linear or branchedC₁˜C₅ alkyl group, which may be substituted, and m, n, and o areintegers ranging from 1 to 10.

wherein R₃ may be a hydrogen (H) or a linear or branched C₁˜C₅ alkylgroup, which may be substituted, a C₃˜C₈ cycloalkyl group, which may besubstituted, or a C₅˜C₁₂ aromatic group, which may be substituted, and xand y are integers ranging from 0 to 5.

wherein R₄˜R₉ are individually H or a linear or branched C₁˜₅ alkylgroup which is substituted or not, a and b are an integer ranging from 1to 100, and w and z are an integer ranging from 0 to 5.

wherein R₁₀ is (CH₂)_(k)Si(OR′)₃, R′ may be a hydrogen (H) or a linearor branched C₁˜C₁₀ alkyl group, and k is an integer ranging from 1 to10.

For example, Formula 4 may bePSS-[2-(3,4-epoxycyclohexyl)ethyl]-heptaisobutyl substituted, Formula 5may bepoly[dimethylsiloxane-co-(2-(3,4-epoxycylohexyl)ethyl)methylsiloxane],Formula 6 may be PSS-octa(trimethoxysilylmethyl) substituted orPSS-octa(trimethoxysilylethyl) substituted PSS. In one embodiment, NCH087 (Nissan Industrial Chemical) may be used.

The organic solvent is selected from the group consisting of methyl3-methoxypropionate, ethyl 3-ethoxypropionate, propyleneglylcolmethyletheracetate, cyclohexanone, 2-heptanone, ethyl lactate, andcombinations thereof.

The thermal acid generator or photoacid generator is present in anamount ranging from about 1 to 20 parts by weight of 100 parts by weightof the silicon resin. The thermal acid generator is selected from thegroup consisting of Formulas 8 and 9.

wherein A is a functional group including a sulfonyl group, and j is 0or 1. The sulfonyl group is

For example, the thermal acid generator may be 2-hydroxylhexylp-toluenylsulfonate.

The photoacid generator is selected from the group consisting ofphthalimidotrifluoro methanesulfonate, dinitrobenzyltosylate,n-decyldisulfone, naphthylimidotrifluoro methanesulfonate, diphenylp-methoxyphenyl sulfonium triflate, diphenyl p-toluenyl sulfoniumtriflate, diphenyl p-isobutylphenyl sulfonium triflate, triphenylhexafluoro arsenate, triphenylhexafluoro antimonite, triphenylsulfoniumtriflate, and dibutylnaphthylsulfonium triflate.

The multi-functional hard mask film may contain a large amount of Si inorder to secure the etching resistance to the amorphous carbon layer orthe lower layer. The multi-functional hard mask film is not affected bytopology, because the multi-functional hard mask film is formed by aspin coating method. Furthermore, the multi-functional hard mask filmmay include a polymer having a hydroxyl group for cross-linking in thecomposition, a catalyst such as a cross-linker, a thermal acid generatorand a photoacid generator for activating the cross-linking, and an opticabsorbent having a large optical density in a wavelength band of anexposure light source.

FIGS. 4 a through 4 e are cross-sectional diagram illustrating a methodfor forming a dual damascene pattern according to a specific embodimentconsistent with the present invention.

An SAC insulating film 113, a first low dielectric film 115, a nitridefilm 117, and a second low dielectric film 119 are sequentiallydeposited over a hardwiring layer 111, and the resulting structure isetched to expose a part of hardwiring layer 111, thereby obtaining a viahole 120 (see FIG. 4 a).

Any material having a low-K value can be used as second dielectric film119. Second dielectric film 119 is selected from the group consisting ofan oxide film, a spin-on glass (SOG) material, and a nitride film. Theoxide film is selected from the group consisting of High Density Plasma(HDP) oxide, Borophosphosilicate Glass (BPSG), and Tetra-ethoxysilicateglass (TEOS). The SOG material is selected from the group consisting ofHydrogen Silses-Quioxane (HSQ), Methyl Silses-Quioxane (MSQ), and PhenylSilses-Quioxane (PSQ). The nitride film is selected from the groupconsisting of Silicon Oxynitride (SiON) and Silicon Rich Oxy-Nitride(SRON).

A multi-functional hard mask film 121 is formed on second dielectricfilm 119 and in via hole 120 by a spin-on coating method (see FIG. 4 b).

A substrate reflectivity can be adjusted by optical constants, such as arefractive index (n) and an absorptivity (k), and a coating thickness ofthe material. A patterning process is facilitated by a low substratereflectivity. However, while it is difficult to change the refractiveindex (n) due to its dependence on the main chain size of a polymer, theabsorptivity or the coating thickness can be easily adjusted by theloading amount of chromophore. In order to lower the substratereflectivity and increase the uniformity of a critical dimension, it isrequired to properly adjust the coating thickness of themulti-functional hard mask film.

For example, multi-functional hard mask film 121 may include a siliconresin present in an amount ranging from about 30 to 70 parts by weightbased on the total weight of the composition as a main element, and hasa refractive index ranging from about 1.6 to 1.8. The silicon resincontains silicon molecules present in an amount ranging from about 20 to45 wt % based on the total weight of the resin. Multi-functional hardmask film 121 is formed to have the substrate reflectivity of less than1%, preferably ranging from about 0.05 to 0.001%. Specifically,multi-functional hard mask film 121 is formed at a thickness rangingfrom about 300 to 1300 Å, preferably from about 300 to 500 Å or fromabout 800 to 1000 Å, more preferably from about 340 to 460 Å, toentirely fill via hole 120 and to reduce the substrate reflectivity.

It is not necessary to form an anti-reflection film in a subsequentprocess, because multi-functional hard mask film 121 controls thesubstrate reflectivity like a conventional anti-reflection film, therebysimplifying the process.

Due to coating effects of multi-functional hard mask film 121, a void orstep coverage is not generated when a separated via hole region or adense region is filled. Also, multi-functional hard mask film 121 is notintermixed with the photoresist material in an interface.

A photoresist pattern 123 is formed over a given region ofmulti-functional hard mask film 121 (see FIG. 4 c).

An etching process is performed on the resulting structure to expose apart of first dielectric film 115 using photoresist pattern 123 as anetching mask, thereby obtaining a trench 125 having a larger width thanthat of via hole 120 (see FIG. 4 d).

Trench 125 is for forming a dual damascene pattern where a via trenchand a conductive trench are deposited.

The etching process described above is performed using a plasma etchinggas selected from the group consisting of CF₄, C₄F₆, CH₂F₂, CHF₃, O₂,Ar, and mixtures thereof as a source gas.

A strip process is performed on the resulting structure to removephotoresist pattern 123 and multi-functional hard mask film 121. A metalmaterial 127 is filled in trench 125 to form a metal line (see FIG. 4e).

The strip process described above is performed by a wet method using achemical such as a fluorine or alkali chemical.

Multi-functional hard mask film 121 may act as a gap fill materialcontaining a large amount of silicon to control the substratereflectivity, so as not to perform a process for forming ananti-reflection film, thereby simplifying the process.

The gap fill material used in a dual damascene process is required tohave a proper etching speed in comparison with first and seconddielectric films 115 and 119. When using multi-functional hard mask film121 as a gap fill material, the etching rate can be adjusted dependingon the silicon content.

When the etching speed of the gap fill material in the process forforming trench 125 is slower than that of second low dielectric film119, defects such as a crown or a fence may be generated one the surfaceof second low dielectric film 119 in the trench, thereby degrading thedeposition effect of seed layers or plating effect of metal materials.When the etching speed of the gap fill material in the trench process isfaster than that of first low dielectric film 115, the lower part of viahole 120 may be etched to damage hardwiring layer 111. When a porousdielectric film is used as a low dielectric film, the etching speed ofmulti-functional hard mask film 121 may be required to be faster thanwhen trench 125 is etched.

In one embodiment, multi-functional hard mask film 121 is used as a gapfill material by regulating the silicon content to obtain a properetching rate, so that various types of low dielectric films can be used.

The above-described multi-functional hard mask film 121 will bedescribed in detail by referring to examples below, which are notintended to limit the scope of the invention.

Example 1 Coating Experiment of a Multi-Functional Hard Mask

Ti/TiN/TiN (340 Å), tungsten (500 Å), and a hard mask nitride film (1500Å) are deposited over a semiconductor substrate and etched to form a bitline pattern. A multi-functional hard mask film (NCH 087, NissanIndustrial Chemical) is spin-coated at a thickness of 1300 Å. Across-section of the resulting structure is measured at a tilt angle of60° and 90° using an SEM.

The multi-functional hard mask film is formed without any void at a 90°tilt angle (see FIG. 5 a) and a 60° tilt angle (see FIG. 5 b).

Example 2 Measurement of a Substrate Reflectivity after Coating of aMulti-Functional Hard Mask Film

An HDP oxide film and a multi-functional hard mask film (NCH 087, NissanIndustrial Chemical) are deposited over an underlying layer to have adifferent thickness from each other. The multi-functional hard mask filmis formed by a spin-coating method. The substrate reflectivity (axis Y)is measured depending on the absorptivity and the coating thickness(axis X) of the multi-functional hard mask. FIGS. 6 a through 6 d showthe results.

When the coating thickness of the multi-functional hard mask film rangesfrom about 300 to 500 Å (k ranges from about 0.3 to 0.6) or from about800 to 1000 Å (k ranges from about 0.2 to 0.5), the substratereflectivity is less than 1.0%. When the coating thickness of the hardmask film formed over the low dielectric film ranges from about 340 to640 Å, k ranges from about 0.4 to 0.5 (see FIGS. 6 a through 6 c).

FIG. 6 d shows an absorptivity value obtained by changing the coatingthickness of the multi-functional hard mask film formed over the HDPoxide film. In order to obtain a stable patterning process condition, aproper coating thickness (over 300 Å) of the multi-functional hard maskis changed depending on the HDP thickness.

When the coating thickness of the multi-functional hard mask film formedover the low dielectric film is higher, the damage amount of photoresistis large during etching of the trench. As a result, a minimum coatingthickness is required like an organic anti-reflection film.

As described above, according to an embodiment consistent with thepresent invention, a multi-functional hard mask material containing alarge amount of silicon is used as a gap fill material in a dualdamascene process. Because the multi-functional hard mask film hascharacteristics of a gap fill material and an anti-reflection film toregulate a substrate reflectivity, it is not necessary to form ananti-reflection film, thereby simplifying the process. Also, the siliconcontent included in the multi-functional hard mask film is regulated toobtain a proper etching rate of a low dielectric film.

The above embodiments of the present invention are illustrative and notlimitative. Various alternatives and equivalents are possible. Theinvention is not limited by the lithography steps described herein. Noris the invention limited to any specific types of semiconductor devices.For example, the present invention may be implemented in a dynamicrandom access memory (DRAM) device or a non-volatile memory device.Other additions, subtractions, or modifications are obvious in view ofthe present disclosure and are intended to fall within the scope of theappended claims.

1. A method for forming a dual damascene pattern, the method comprising:preparing a multi-functional hard mask composition including a siliconresin as a base resin, wherein the silicon resin comprises about 20 to45% silicon molecules by weight, based on a total weight of the resin;forming a deposition structure by sequentially forming aself-arrangement contact (SAC) insulating film, a first dielectric film,an etching barrier film, and a second dielectric film over a hardwiringlayer; etching the deposition structure to expose the hardwiring layer,thereby forming a via hole; coating the multi-functional hard maskcomposition over the second dielectric film and in the via hole to forma multi-functional hard mask film; and etching the resulting structureto expose a part of the first dielectric film using a photoresistpattern as an etching mask, thereby forming a trench having a widthgreater than that of the via hole.
 2. The method according to claim 1,further comprising: removing the multi-functional hard mask film; andfilling a metal material in the trench to form a metal line.
 3. Themethod according to claim 1, wherein the multi-functional hard maskcomposition comprises i) a silicon resin present in an amount rangingfrom about 30 to 70 parts by weight based on 100 parts by weight of thecomposition, and ii) a residual organic solvent as main elements;optionally iii) a compound represented by Formula 1 or Formula 2; andoptionally iv) a thermal acid generator or a photoacid generator:

wherein R_(a)˜R_(d) are individually hydrogen, or a linear or branchedC₁˜C₅ alkyl group, which may be substituted, e is an integer rangingfrom 5 to 500, f is an integer ranging from 0 to 5, and g is an integerranging from 1 to
 5. 4. The method according to claim 3, wherein themolecular weight of the silicon resin ranges from about 300 to 30,000.5. The method according to claim 3, wherein the compound represented byFormula 1 or Formula 2 is present in an amount ranging from about 20 to200 parts by weight based on 100 parts by weight of the silicon resin.6. The method according to claim 3, wherein the thermal acid generatoror the photoacid generator is present in an amount ranging from about 1to 20 parts by weight based on 100 parts by weight of the silicon resin.7. The method according to claim 3, wherein the silicon resin includesone or more compounds selected from compounds represented by Formula 3and Formula 4:

wherein R₁ and R₂ are individually hydrogen or a linear or branchedC₁˜C₅ alkyl group, which may be substituted; R₃ is hydrogen or a linearor branched C₁˜C₅ alkyl group, which may be substituted, a C₃˜C₈cycloalkyl group, which may be substituted, or a C₅˜C₁₂ aromatic group,which may be substituted; m, n and o are integers ranging from 1 to 10;and x and y are integers ranging from 0 to
 5. 8. The method according toclaim 3, wherein the organic solvent is selected from the groupconsisting of methyl 3-methoxypropionate, ethyl 3-ethoxypropionate,propyleneglycol methyletheracetate, cyclohexanone, 2-heptanone, ethyllactate, and combinations thereof.
 9. The method according to claim 3,wherein the thermal acid generator is a compound represented by Formula8 or Formula 9:

wherein A is a functional group including a sulfonic group, and n is 0or
 1. 10. The method according to claim 3, wherein the photoacidgenerator is selected from the group consisting of phthalimidotrifluoromethanesulfonate, dinitrobenzyltosylate, n-decyldisulfone,naphtylimidotrifluoro methanesulfonate, diphenyl p-methoxyphenylsulfonium triflate, diphenyl p-toluenyl sulfonium triflate, diphenylp-isobutylphenyl sulfonium triflate, triphenyl hexafluoro arsenate,triphenylhexafluoro antimonite, triphenylsulfonium triflate, anddibutylnaphtylsulfonium triflate.
 11. The method according to claim 1,wherein the second dielectric film comprises at least one of an oxidefilm, a spin-on-glass material film, and a nitride film.
 12. The methodaccording to claim 11, wherein: the oxide film is selected from thegroup consisting of High Density Plasma (HDP), Borophosphosilicate Glass(BPSG), and Tetra-ethoxysilicate glass (TEOS); the spin-on-glassmaterial is selected from the group consisting of HydrogenSilses-Quioxane (HSQ), Methyl Silses-Quioxane (MSQ), and PhenylSilses-Quioxane (PSQ); and the nitride film is one of Oxynitride (SiON)or Silicon Rich Oxy-Nitride (SRON).
 13. The method according to claim 1,wherein the multi-functional hard mask film has a refractive indexranging from about 1.6 to 1.8.
 14. The method according to claim 1,wherein the multi-functional hard mask film is formed to have a coatingthickness such that a substrate reflectivity is below 1%.
 15. The methodaccording to claim 14, wherein the substrate reflectivity ranges fromabout 0.05 to 0.001%.
 16. The method according to claim 1, wherein thetrench is formed by using a plasma etching gas selected from the groupconsisting of CF₄, C₄F₆, CH₂F₂, CHF₃, O₂, Ar, and mixtures thereof. 17.The method according to claim 1, wherein theremoving-the-multi-functional-hard-mask comprises performing a wetetching process using a fluorine or alkali chemical.